(1) Field of Invention
Air operated muffled hammers.
(2) Prior Art
This invention relates to air hammers of the reciprocating piston type in which pressurized air, delivered through a manual inlet valve and an automatic control valve to a control bore in the hammer barrel, drives the piston on its power stroke and, upon the piston delivering its blow, drives the piston on its return stroke. These strokes alternate repeatedly in succession so long as the pressurized air admitted to the hammer bore by setting of the manual inlet valve remains in open condition. At the end of each stroke, the pressurized air is exhausted from the hammer bore to the atmosphere, causing particularly loud and irritating noise.
Heretofore such hammers have been provided with mufflers which embrace all or part of the hammer barrel. Such mufflers somtimes are torn open or removed. However, the workmen and service men quite often do not repair or replace the torn open or removed muffler with the result that the noise abatement is no longer effected. These mufflers are an addition to the original prior hammers and are an additional cost. The prior hammers are operable with or without the muffler.